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Lanning NT, Jiang S, Amaral VJ, Mateos K, Steffen JM, Lam PJ, Boyle EA, Fitzsimmons JN. Isotopes illustrate vertical transport of anthropogenic Pb by reversible scavenging within Pacific Ocean particle veils. Proc Natl Acad Sci U S A 2023; 120:e2219688120. [PMID: 37252961 PMCID: PMC10265975 DOI: 10.1073/pnas.2219688120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 04/27/2023] [Indexed: 06/01/2023] Open
Abstract
Reversible scavenging, the oceanographic process by which dissolved metals exchange onto and off sinking particles and are thereby transported to deeper depths, has been well established for the metal thorium for decades. Reversible scavenging both deepens the elemental distribution of adsorptive elements and shortens their oceanic residence times in the ocean compared to nonadsorptive metals, and scavenging ultimately removes elements from the ocean via sedimentation. Thus, it is important to understand which metals undergo reversible scavenging and under what conditions. Recently, reversible scavenging has been invoked in global biogeochemical models of a range of metals including lead, iron, copper, and zinc to fit modeled data to observations of oceanic dissolved metal distributions. Nonetheless, the effects of reversible scavenging remain difficult to visualize in ocean sections of dissolved metals and to distinguish from other processes such as biological regeneration. Here, we show that particle-rich "veils" descending from high-productivity zones in the equatorial and North Pacific provide idealized illustrations of reversible scavenging of dissolved lead (Pb). A meridional section of dissolved Pb isotope ratios across the central Pacific shows that where particle concentrations are sufficiently high, such as within particle veils, vertical transport of anthropogenic surface-dissolved Pb isotope ratios toward the deep ocean is manifested as columnar isotope anomalies. Modeling of this effect shows that reversible scavenging within particle-rich waters allows anthropogenic Pb isotope ratios from the surface to penetrate ancient deep waters on timescales sufficiently rapid to overcome horizontal mixing of deep water Pb isotope ratios along abyssal isopycnals.
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Affiliation(s)
- Nathan T. Lanning
- Department of Oceanography, Texas A&M University, College Station, TX77840
| | - Shuo Jiang
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA02139
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai200241, China
| | - Vinicius J. Amaral
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, CA95064
| | - Katherine Mateos
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, CA95064
| | - Janelle M. Steffen
- Department of Oceanography, Texas A&M University, College Station, TX77840
| | - Phoebe J. Lam
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, CA95064
| | - Edward A. Boyle
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA02139
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2
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Krisch S, Hopwood MJ, Schaffer J, Al-Hashem A, Höfer J, Rutgers van der Loeff MM, Conway TM, Summers BA, Lodeiro P, Ardiningsih I, Steffens T, Achterberg EP. The 79°N Glacier cavity modulates subglacial iron export to the NE Greenland Shelf. Nat Commun 2021; 12:3030. [PMID: 34031401 PMCID: PMC8144390 DOI: 10.1038/s41467-021-23093-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 04/14/2021] [Indexed: 02/04/2023] Open
Abstract
Approximately half of the freshwater discharged from the Greenland and Antarctic Ice Sheets enters the ocean subsurface as a result of basal ice melt, or runoff draining via the grounding line of a deep ice shelf or marine-terminating glacier. Around Antarctica and parts of northern Greenland, this freshwater then experiences prolonged residence times in large cavities beneath floating ice tongues. Due to the inaccessibility of these cavities, it is unclear how they moderate the freshwater associated supply of nutrients such as iron (Fe) to the ocean. Here, we show that subglacial dissolved Fe export from Nioghalvfjerdsbrae (the '79°N Glacier') is decoupled from particulate inputs including freshwater Fe supply, likely due to the prolonged ~162-day residence time of Atlantic water beneath Greenland's largest floating ice-tongue. Our findings indicate that the overturning rate and particle-dissolved phase exchanges in ice cavities exert a dominant control on subglacial nutrient supply to shelf regions.
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Affiliation(s)
- Stephan Krisch
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | | | - Janin Schaffer
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Ali Al-Hashem
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - Juan Höfer
- Escuela de Ciencias del Mar, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | | | - Tim M Conway
- College of Marine Science, University of South Florida, St Petersburg, FL, USA
| | - Brent A Summers
- College of Marine Science, University of South Florida, St Petersburg, FL, USA
| | - Pablo Lodeiro
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
- Department of Chemistry, University of Lleida - Agrotecnio-Cerca Centre, Lleida, Spain
| | - Indah Ardiningsih
- NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, Den Burg, Texel, The Netherlands
| | - Tim Steffens
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
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3
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Snow JT, Holdship P, Rickaby REM. Antagonistic co-limitation through ion promiscuity - On the metal sensitivity of Thalassiosira oceanica under phosphorus stress. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 699:134080. [PMID: 31677461 DOI: 10.1016/j.scitotenv.2019.134080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/08/2019] [Accepted: 08/22/2019] [Indexed: 06/10/2023]
Abstract
Nutrient limitation of primary producers is a fundamental principle in biogeochemical oceanography and has been used with great success in prescribing understanding to patterns of marine primary productivity. In recent years the paradigm of nutrient limitation has expanded from single nutrient limitation towards concepts of co-limitation by multiple resources. Interactive effects between multiple limiting resources are now thought commonplace in marine microbial communities. Here we investigate the response exhibited by phosphate-limited Thalassiosira oceanica to elevated concentrations of the phosphate analogs vanadate, arsenate and molybdate. Enrichments in external arsenate and vanadate to phosphate-limited cultures act to suppress growth rates entirely, an effect not seen in phosphate replete conditions. Retardation of growth rates is attributed to mistaken uptake through ion promiscuity as evidenced by observations of significant intracellular accumulation of both arsenic and vanadium under phosphate limited conditions. We describe this novel co-limitation scenario as dependent antagonistic co-limitation (DAC), and suggest that this phenomenon of non-deliberate intracellular accumulation could be used as both a proxy of phosphate stress in the modern ocean and a possible marker of phosphate depletion limiting the duration of oceanic anoxic events.
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Affiliation(s)
- Joseph T Snow
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK.
| | - Philip Holdship
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK
| | - Rosalind E M Rickaby
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK.
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4
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Perron MMG, Strzelec M, Gault-Ringold M, Proemse BC, Boyd PW, Bowie AR. Assessment of leaching protocols to determine the solubility of trace metals in aerosols. Talanta 2019; 208:120377. [PMID: 31816697 DOI: 10.1016/j.talanta.2019.120377] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 09/17/2019] [Accepted: 09/18/2019] [Indexed: 10/26/2022]
Abstract
Atmospheric deposition of aerosols to the ocean provides an important pathway for the supply of vital micronutrients, including trace metals. These trace metals are essential for phytoplankton growth, and therefore their delivery to marine ecosystems can strongly influence the ocean carbon cycle. The solubility of trace metals in aerosols is a key parameter to better constrain their potential impact on phytoplankton growth. To date, a wide range of experimental approaches and nomenclature have been used to define aerosol trace metal solubility, making data comparison between studies difficult. Here we investigate and discuss several laboratory leaching protocols to determine the solubility of key trace metals in aerosol samples, namely iron, cobalt, manganese, copper, lead, vanadium, titanium and aluminium. Commonly used techniques and tools are also considered such as enrichment factor calculations and air mass back-trajectory projections and recommendations are given for aerosol field sampling, laboratory processing (including leaching and digestion) and analytical measurements. Finally, a simple 3-step leaching protocol combining commonly used protocols is proposed to operationally define trace metal solubility in aerosols. The need for standard guidelines and protocols to study the biogeochemical impact of atmospheric trace metal deposition to the ocean has been increasingly emphasised by both the atmospheric and oceanographic communities. This lack of standardisation currently limits our understanding and ability to predict ocean and climate interactions under changing environmental conditions.
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Affiliation(s)
- Morgane M G Perron
- Institute for Marine and Antarctic Studies, University of Tasmania, Battery Point, Tasmania, Australia.
| | - Michal Strzelec
- Institute for Marine and Antarctic Studies, University of Tasmania, Battery Point, Tasmania, Australia
| | - Melanie Gault-Ringold
- Antarctic Climate and Ecosystems CRC, University of Tasmania, Battery Point, Tasmania, Australia
| | - Bernadette C Proemse
- Institute for Marine and Antarctic Studies, University of Tasmania, Battery Point, Tasmania, Australia
| | - Philip W Boyd
- Institute for Marine and Antarctic Studies, University of Tasmania, Battery Point, Tasmania, Australia; Antarctic Climate and Ecosystems CRC, University of Tasmania, Battery Point, Tasmania, Australia
| | - Andrew R Bowie
- Institute for Marine and Antarctic Studies, University of Tasmania, Battery Point, Tasmania, Australia; Antarctic Climate and Ecosystems CRC, University of Tasmania, Battery Point, Tasmania, Australia
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5
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Major lithogenic contributions to the distribution and budget of iron in the North Pacific Ocean. Sci Rep 2019; 9:11652. [PMID: 31406147 PMCID: PMC6690902 DOI: 10.1038/s41598-019-48035-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 07/29/2019] [Indexed: 11/28/2022] Open
Abstract
Recent studies have elucidated that iron (Fe) is a critical trace metal that influences the productivity of marine ecosystems and the biogeochemical cycles of other elements in the modern ocean. However, our understanding of the biogeochemistry of Fe remains incomplete. Herein, we report basin-scale and full-depth sectional distributions of total dissolvable iron (tdFe), dissolved iron (dFe), and labile particulate iron (lpFe = tdFe – dFe) in the North Pacific Ocean, as observed during three cruises of the GEOTRACES Japan program. We found that lpFe dominates tdFe and is significantly correlated with labile particulate aluminum (lpAl): lpFe [nmol kg−1] = (0.544 ± 0.005) lpAl [nmol kg−1] + 0.11 ± 0.04, r2 = 0.968, n = 432. The results indicate a major lithogenic contribution to the distribution of particulate Fe. For dFe, the unique distribution is attributed to the combined effects of biogeochemical cycling, manganese reduction, and lithogenic contribution. Based on concurrent observations of Fe, Al, and manganese (Mn), we infer that the width of the boundary scavenging zone is approximately 500 km off the Aleutian shelf. We estimate the inventory of tdFe in the North Pacific as 1.1 × 1012 mol, which is approximately four times that of dFe. Our results emphasize the potential importance of lpFe in the ocean’s iron cycle.
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Garcia CA, Baer SE, Garcia NS, Rauschenberg S, Twining BS, Lomas MW, Martiny AC. Nutrient supply controls particulate elemental concentrations and ratios in the low latitude eastern Indian Ocean. Nat Commun 2018; 9:4868. [PMID: 30451846 PMCID: PMC6242840 DOI: 10.1038/s41467-018-06892-w] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 09/14/2018] [Indexed: 11/17/2022] Open
Abstract
Variation in ocean C:N:P of particulate organic matter (POM) has led to competing hypotheses for the underlying drivers. Each hypothesis predicts C:N:P equally well due to regional co-variance in environmental conditions and biodiversity. The Indian Ocean offers a unique positive temperature and nutrient supply relationship to test these hypotheses. Here we show how elemental concentrations and ratios vary over daily and regional scales. POM concentrations were lowest in the southern gyre, elevated across the equator, and peaked in the Bay of Bengal. Elemental ratios were highest in the gyre, but approached Redfield proportions northwards. As Prochlorococcus dominated the phytoplankton community, biodiversity changes could not explain the elemental variation. Instead, our data supports the nutrient supply hypothesis. Finally, gyre dissolved iron concentrations suggest extensive iron stress, leading to depressed ratios compared to other gyres. We propose a model whereby differences in iron supply and N2-fixation influence C:N:P levels across ocean gyres.
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Affiliation(s)
- Catherine A Garcia
- Department of Earth System Science, University of California at Irvine, Irvine, CA, 92617, USA
| | - Steven E Baer
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, 04544, USA
- Maine Maritime Academy, Castine, ME, 04420, USA
| | - Nathan S Garcia
- Department of Earth System Science, University of California at Irvine, Irvine, CA, 92617, USA
| | - Sara Rauschenberg
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, 04544, USA
| | | | - Michael W Lomas
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, 04544, USA
| | - Adam C Martiny
- Department of Earth System Science, University of California at Irvine, Irvine, CA, 92617, USA.
- Department of Ecology and Evolution, University of California at Irvine, Irvine, CA, 92617, USA.
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7
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Sherrell RM, Annett AL, Fitzsimmons JN, Roccanova VJ, Meredith MP. A 'shallow bathtub ring' of local sedimentary iron input maintains the Palmer Deep biological hotspot on the West Antarctic Peninsula shelf. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2018; 376:rsta.2017.0171. [PMID: 29760114 PMCID: PMC5954470 DOI: 10.1098/rsta.2017.0171] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/21/2018] [Indexed: 05/23/2023]
Abstract
Palmer Deep (PD) is one of several regional hotspots of biological productivity along the inner shelf of the West Antarctic Peninsula. The proximity of hotspots to shelf-crossing deep troughs has led to the 'canyon hypothesis', which proposes that circumpolar deep water flowing shoreward along the canyons is upwelled on the inner shelf, carrying nutrients including iron (Fe) to surface waters, maintaining phytoplankton blooms. We present here full-depth profiles of dissolved and particulate Fe and manganese (Mn) from eight stations around PD, sampled in January and early February of 2015 and 2016, allowing the first detailed evaluation of Fe sources to the area's euphotic zone. We show that upwelling of deep water does not control Fe flux to the surface; instead, shallow sediment-sourced Fe inputs are transported horizontally from surrounding coastlines, creating strong vertical gradients of dissolved Fe within the upper 100 m that supply this limiting nutrient to the local ecosystem. The supply of bioavailable Fe is, therefore, not significantly related to the canyon transport of deep water. Near shore time-series samples reveal that local glacial meltwater appears to be an important Mn source but, surprisingly, is not a large direct Fe input to this biological hotspot.This article is part of the theme issue 'The marine system of the West Antarctic Peninsula: status and strategy for progress in a region of rapid change'.
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Affiliation(s)
- Robert M Sherrell
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901, USA
- Department of Earth and Planetary Sciences, Rutgers University, Piscataway, NJ, USA
| | - Amber L Annett
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901, USA
| | - Jessica N Fitzsimmons
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901, USA
| | - Vincent J Roccanova
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901, USA
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8
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Klar JK, Homoky WB, Statham PJ, Birchill AJ, Harris EL, Woodward EMS, Silburn B, Cooper MJ, James RH, Connelly DP, Chever F, Lichtschlag A, Graves C. Stability of dissolved and soluble Fe(II) in shelf sediment pore waters and release to an oxic water column. BIOGEOCHEMISTRY 2017; 135:49-67. [PMID: 32009691 PMCID: PMC6961528 DOI: 10.1007/s10533-017-0309-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 02/06/2017] [Indexed: 05/28/2023]
Abstract
Shelf sediments underlying temperate and oxic waters of the Celtic Sea (NW European Shelf) were found to have shallow oxygen penetrations depths from late spring to late summer (2.2-5.8 mm below seafloor) with the shallowest during/after the spring-bloom (mid-April to mid-May) when the organic carbon content was highest. Sediment porewater dissolved iron (dFe, <0.15 µm) mainly (>85%) consisted of Fe(II) and gradually increased from 0.4 to 15 μM at the sediment surface to ~100-170 µM at about 6 cm depth. During the late spring this Fe(II) was found to be mainly present as soluble Fe(II) (>85% sFe, <0.02 µm). Sub-surface dFe(II) maxima were enriched in light isotopes (δ56Fe -2.0 to -1.5‰), which is attributed to dissimilatory iron reduction (DIR) during the bacterial decomposition of organic matter. As porewater Fe(II) was oxidised to insoluble Fe(III) in the surface sediment layer, residual Fe(II) was further enriched in light isotopes (down to -3.0‰). Ferrozine-reactive Fe(II) was found in surface porewaters and in overlying core top waters, and was highest in the late spring period. Shipboard experiments showed that depletion of bottom water oxygen in late spring can lead to a substantial release of Fe(II). Reoxygenation of bottom water caused this Fe(II) to be rapidly lost from solution, but residual dFe(II) and dFe(III) remained (12 and 33 nM) after >7 h. Iron(II) oxidation experiments in core top and bottom waters also showed removal from solution but at rates up to 5-times slower than predicted from theoretical reaction kinetics. These data imply the presence of ligands capable of complexing Fe(II) and supressing oxidation. The lower oxidation rate allows more time for the diffusion of Fe(II) from the sediments into the overlying water column. Modelling indicates significant diffusive fluxes of Fe(II) (on the order of 23-31 µmol m-2 day-1) are possible during late spring when oxygen penetration depths are shallow, and pore water Fe(II) concentrations are highest. In the water column this stabilised Fe(II) will gradually be oxidised and become part of the dFe(III) pool. Thus oxic continental shelves can supply dFe to the water column, which is enhanced during a small period of the year after phytoplankton bloom events when organic matter is transferred to the seafloor. This input is based on conservative assumptions for solute exchange (diffusion-reaction), whereas (bio)physical advection and resuspension events are likely to accelerate these solute exchanges in shelf-seas.
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Affiliation(s)
- J. K. Klar
- Ocean and Earth Science, National Oceanography Centre, University of Southampton, Southampton, SO14 3ZH UK
- Present Address: LEGOS, Université de Toulouse, CNES, CNRS, IRD, UPS, 14 Avenue Edouard Belin, 31400 Toulouse, France
| | - W. B. Homoky
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, OX1 3AN UK
| | - P. J. Statham
- Ocean and Earth Science, National Oceanography Centre, University of Southampton, Southampton, SO14 3ZH UK
| | - A. J. Birchill
- School of Geography, Earth and Environmental Science, University of Plymouth, Drake Circus, Plymouth, PL4 8AA UK
| | - E. L. Harris
- Ocean and Earth Science, National Oceanography Centre, University of Southampton, Southampton, SO14 3ZH UK
| | - E. M. S. Woodward
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH UK
| | - B. Silburn
- Centre for Environment, Fisheries and Aquaculture Science, Pakefield Road, Lowestoft, NR33 0HT UK
| | - M. J. Cooper
- Ocean and Earth Science, National Oceanography Centre, University of Southampton, Southampton, SO14 3ZH UK
| | - R. H. James
- Ocean and Earth Science, National Oceanography Centre, University of Southampton, Southampton, SO14 3ZH UK
| | - D. P. Connelly
- Marine Geosciences, National Oceanography Centre, European Way, Southampton, SO14 3ZH UK
| | - F. Chever
- Ocean and Earth Science, National Oceanography Centre, University of Southampton, Southampton, SO14 3ZH UK
| | - A. Lichtschlag
- Marine Geosciences, National Oceanography Centre, European Way, Southampton, SO14 3ZH UK
| | - C. Graves
- Ocean and Earth Science, National Oceanography Centre, University of Southampton, Southampton, SO14 3ZH UK
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9
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Homoky WB, Weber T, Berelson WM, Conway TM, Henderson GM, van Hulten M, Jeandel C, Severmann S, Tagliabue A. Quantifying trace element and isotope fluxes at the ocean-sediment boundary: a review. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2016; 374:rsta.2016.0246. [PMID: 29035270 PMCID: PMC5069539 DOI: 10.1098/rsta.2016.0246] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/24/2016] [Indexed: 05/23/2023]
Abstract
Quantifying fluxes of trace elements and their isotopes (TEIs) at the ocean's sediment-water boundary is a pre-eminent challenge to understand their role in the present, past and future ocean. There are multiple processes that drive the uptake and release of TEIs, and properties that determine their rates are unevenly distributed (e.g. sediment composition, redox conditions and (bio)physical dynamics). These factors complicate our efforts to find, measure and extrapolate TEI fluxes across ocean basins. GEOTRACES observations are unveiling the oceanic distributions of many TEIs for the first time. These data evidence the influence of the sediment-water boundary on many TEI cycles, and underline the fact that our knowledge of the source-sink fluxes that sustain oceanic distributions is largely missing. Present flux measurements provide low spatial coverage and only part of the empirical basis needed to predict TEI flux variations. Many of the advances and present challenges facing TEI flux measurements are linked to process studies that collect sediment cores, pore waters, sinking material or seawater in close contact with sediments. However, such sampling has not routinely been viable on GEOTRACES expeditions. In this article, we recommend approaches to address these issues: firstly, with an interrogation of emergent data using isotopic mass-balance and inverse modelling techniques; and secondly, by innovating pursuits of direct TEI flux measurements. We exemplify the value of GEOTRACES data with a new inverse model estimate of benthic Al flux in the North Atlantic Ocean. Furthermore, we review viable flux measurement techniques tailored to the sediment-water boundary. We propose that such activities are aimed at regions that intersect the GEOTRACES Science Plan on the basis of seven criteria that may influence TEI fluxes: sediment provenance, composition, organic carbon supply, redox conditions, sedimentation rate, bathymetry and the benthic nepheloid inventory.This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.
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Affiliation(s)
- William B Homoky
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK
| | - Thomas Weber
- School of Oceanography, University of Washington, 1503 NE Boat Street, Seattle, WA 98105, USA
| | - William M Berelson
- Department of Earth Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Tim M Conway
- Department of Earth Sciences, ETH Zürich, Clausiusstrasse 25, 8092 Zürich, Switzerland
- College of Marine Science, University of South Florida, St Petersburg, FL 33701, USA
| | - Gideon M Henderson
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK
| | - Marco van Hulten
- Laboratoire des Sciences du Climat et de l'Environnement (LSCE), IPSL, CEA-Orme des Merisiers, 91191 Gif-sur-Yvette, France
| | - Catherine Jeandel
- Laboratoire d'Etudes en Géophysique et Océanographie Spatiales (LEGOS), 14 Avenue Edouard Belin, 31400 Toulouse, France
| | - Silke Severmann
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901, USA
| | - Alessandro Tagliabue
- School of Environmental Sciences, University of Liverpool, Jane Herdman Building, Liverpool L69 3GP, UK
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10
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Anderson RF, Cheng H, Edwards RL, Fleisher MQ, Hayes CT, Huang KF, Kadko D, Lam PJ, Landing WM, Lao Y, Lu Y, Measures CI, Moran SB, Morton PL, Ohnemus DC, Robinson LF, Shelley RU. How well can we quantify dust deposition to the ocean? PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2016; 374:rsta.2015.0285. [PMID: 29035251 DOI: 10.1098/rsta.2015.02852016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Accepted: 08/10/2016] [Indexed: 05/25/2023]
Abstract
Deposition of continental mineral aerosols (dust) in the Eastern Tropical North Atlantic Ocean, between the coast of Africa and the Mid-Atlantic Ridge, was estimated using several strategies based on the measurement of aerosols, trace metals dissolved in seawater, particulate material filtered from the water column, particles collected by sediment traps and sediments. Most of the data used in this synthesis involve samples collected during US GEOTRACES expeditions in 2010 and 2011, although some results from the literature are also used. Dust deposition generated by a global model serves as a reference against which the results from each observational strategy are compared. Observation-based dust fluxes disagree with one another by as much as two orders of magnitude, although most of the methods produce results that are consistent with the reference model to within a factor of 5. The large range of estimates indicates that further work is needed to reduce uncertainties associated with each method before it can be applied routinely to map dust deposition to the ocean. Calculated dust deposition using observational strategies thought to have the smallest uncertainties is lower than the reference model by a factor of 2-5, suggesting that the model may overestimate dust deposition in our study area.This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.
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Affiliation(s)
- R F Anderson
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA
- Department of Earth and Environmental Sciences, Columbia University, New York, NY 10027, USA
| | - H Cheng
- Department of Earth Sciences, University of Minnesota, Minneapolis, MN 55455, USA
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, People's Republic of China
| | - R L Edwards
- Department of Earth Sciences, University of Minnesota, Minneapolis, MN 55455, USA
| | - M Q Fleisher
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA
| | - C T Hayes
- Department of Marine Science, University of Southern Mississippi, Stennis Space Center, MS 39529, USA
| | - K-F Huang
- Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan, Republic of China
| | - D Kadko
- Applied Research Center, Florida International University, Miami, FL 33174, USA
| | - P J Lam
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - W M Landing
- Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL 32306, USA
| | - Y Lao
- Department of Laboratory Services, Massachusetts Water Resources Authority, 190 Tafts Avenue, Winthrop, MA 02152, USA
| | - Y Lu
- Earth Observatory of Singapore, 50 Nanyang Avenue, Singapore 639798, Republic of Singapore
| | - C I Measures
- Department of Oceanography, University of Hawaii, Honolulu, HI 96822, USA
| | - S B Moran
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| | - P L Morton
- Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL 32306, USA
| | - D C Ohnemus
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME 04544, USA
| | - L F Robinson
- School of Earth Sciences, University of Bristol, Queens Road, Bristol BS8 1RJ, UK
| | - R U Shelley
- LEMAR/UMR CNRS 6539/IUEM, Technopôle Brest-Iroise, Place Nicolas Copernic, Plouzané 29280, France
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Anderson RF, Cheng H, Edwards RL, Fleisher MQ, Hayes CT, Huang KF, Kadko D, Lam PJ, Landing WM, Lao Y, Lu Y, Measures CI, Moran SB, Morton PL, Ohnemus DC, Robinson LF, Shelley RU. How well can we quantify dust deposition to the ocean? PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2016; 374:20150285. [PMID: 29035251 PMCID: PMC5069522 DOI: 10.1098/rsta.2015.0285] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/10/2016] [Indexed: 05/09/2023]
Abstract
Deposition of continental mineral aerosols (dust) in the Eastern Tropical North Atlantic Ocean, between the coast of Africa and the Mid-Atlantic Ridge, was estimated using several strategies based on the measurement of aerosols, trace metals dissolved in seawater, particulate material filtered from the water column, particles collected by sediment traps and sediments. Most of the data used in this synthesis involve samples collected during US GEOTRACES expeditions in 2010 and 2011, although some results from the literature are also used. Dust deposition generated by a global model serves as a reference against which the results from each observational strategy are compared. Observation-based dust fluxes disagree with one another by as much as two orders of magnitude, although most of the methods produce results that are consistent with the reference model to within a factor of 5. The large range of estimates indicates that further work is needed to reduce uncertainties associated with each method before it can be applied routinely to map dust deposition to the ocean. Calculated dust deposition using observational strategies thought to have the smallest uncertainties is lower than the reference model by a factor of 2-5, suggesting that the model may overestimate dust deposition in our study area.This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.
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Affiliation(s)
- R F Anderson
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA
- Department of Earth and Environmental Sciences, Columbia University, New York, NY 10027, USA
| | - H Cheng
- Department of Earth Sciences, University of Minnesota, Minneapolis, MN 55455, USA
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, People's Republic of China
| | - R L Edwards
- Department of Earth Sciences, University of Minnesota, Minneapolis, MN 55455, USA
| | - M Q Fleisher
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA
| | - C T Hayes
- Department of Marine Science, University of Southern Mississippi, Stennis Space Center, MS 39529, USA
| | - K-F Huang
- Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan, Republic of China
| | - D Kadko
- Applied Research Center, Florida International University, Miami, FL 33174, USA
| | - P J Lam
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - W M Landing
- Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL 32306, USA
| | - Y Lao
- Department of Laboratory Services, Massachusetts Water Resources Authority, 190 Tafts Avenue, Winthrop, MA 02152, USA
| | - Y Lu
- Earth Observatory of Singapore, 50 Nanyang Avenue, Singapore 639798, Republic of Singapore
| | - C I Measures
- Department of Oceanography, University of Hawaii, Honolulu, HI 96822, USA
| | - S B Moran
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| | - P L Morton
- Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL 32306, USA
| | - D C Ohnemus
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME 04544, USA
| | - L F Robinson
- School of Earth Sciences, University of Bristol, Queens Road, Bristol BS8 1RJ, UK
| | - R U Shelley
- LEMAR/UMR CNRS 6539/IUEM, Technopôle Brest-Iroise, Place Nicolas Copernic, Plouzané 29280, France
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de Jong J, Schoemann V, Lannuzel D, Croot P, de Baar H, Tison JL. Natural iron fertilization of the Atlantic sector of the Southern Ocean by continental shelf sources of the Antarctic Peninsula. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jg001679] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Bowie AR, Townsend AT, Lannuzel D, Remenyi TA, van der Merwe P. Modern sampling and analytical methods for the determination of trace elements in marine particulate material using magnetic sector inductively coupled plasma–mass spectrometry. Anal Chim Acta 2010; 676:15-27. [DOI: 10.1016/j.aca.2010.07.037] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2010] [Revised: 07/20/2010] [Accepted: 07/22/2010] [Indexed: 10/19/2022]
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Bruland KW, Lohan MC, Aguilar-Islas AM, Smith GJ, Sohst B, Baptista A. Factors influencing the chemistry of the near-field Columbia River plume: Nitrate, silicic acid, dissolved Fe, and dissolved Mn. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jc004702] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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